Sight is one of the most important senses because it allows us to gain knowledge about the world. Without vision, our ability to know your surroundings is limited. In this essay, I will explain the complex structure of the eye, how it works, the properties of vision, and how heterochromia iridis affects the eye. From this essay, the reader will be able to understand the functioning of the eye and acquire the more advanced knowledge bases. The eye has a complex structure made up of many parts. The sclera, or white of the eye, functions to keep the interior of the eye dark and also to provide the “covering of the eye.” Behind the sclera is the cornea which protects the eye. Additionally, it also helps the lens in its light focusing function. Behind the cornea is the aqueous humor which is a watery gel that fills the empty space between the cornea and the iris. The pupil is the opening of the eye that allows light to pass through while the iris, the colored part of the eye, controls the amount of light that passes through the pupil. Behind the iris is the lens which is used to project the image of the outside world onto the retina. The retina acts as the “screen” of the eye and is located at the back, near the optic nerve. It “feels” the light, then sends the image to the brain, via the optic nerve. The optic nerve is the nerve that sends the image to the brain. In front of the retina is the vitreous humor, a gelatinous substance that fills the empty space in the eye. This is about the inner workings of the eye and its complex structure. The essential part of the eye is the projector which projects the image and the screen which detects the image. For vision to work, we must have the lens-cornea pair to act as a project...... middle of paper...... this can cause my eye trauma. Anterior uveitis is an inflammation of the center of the iris and when your iris becomes inflamed you have iritis and both of these inflammations can cause iris heterochromia. Six out of 1,000 people live with heterochromia every day. Some people only have a mild case of heterochromia iridis, so it is very unnoticeable. Most people with heterchromia iridis are due to the fact that the condition is primarily hereditary. Does heterochromia iridis affect your vision. Heterchromia iridis is a very rare, but not dangerous, disease. I hope that with this essay your knowledge about the eye has been expanded and you have a basis for further investigation. Without vision, we could not acquire knowledge of the world. The structure of the eye, how it works and its properties can be very important if you ever have eye problems..